User Guide

Chapter 3 Managing the network access devices 111
Nortel Secure Network Access Switch 4050 User Guide
The switch SSH Key screen appears (see Figure 14 on page 109).
2 Click Delete Switch SSH Key.
3 Click Apply on the toolbar to send the current changes to the Nortel
SNAS 4050. Click Commit on the toolbar to save the changes permanently.
4 Click Import SSH from Switch.
5 Click Apply on the toolbar to send the current changes to the Nortel
SNAS 4050. Click Commit on the toolbar to save the changes permanently.
For more information about the SSH Key commands, see “Managing SSH keys
for Nortel SNA communication using the SREM” on page 109.
Monitoring switch health using the SREM
The Nortel SNAS 4050 continually monitors the health of the network access
devices. At specified intervals, a health check daemon sends queries and
responses to the switch as a heartbeat mechanism. If no activity (heartbeat) is
detected, the daemon will retry the health check for a specified number of times
(the dead count). If there is still no heartbeat, then after a further interval (the
status-quo interval) the network access device moves all its clients into the Red
VLAN. When connectivity is re-established, the Nortel SNAS 4050 synchronizes
sessions with the network access device.
The health check interval, dead count, and status-quo interval are configurable.
To configure parameters for the Nortel SNAS 4050 health checks, complete the
following steps:
1 Select the Secure Access Domain > domain > Switches > switch > Health
Check tab.